FinFET enhanced device of P-GaN cap layer and manufacturing method

Abstract

The invention relates to a FinFET enhanced device of a P-GaN cap layer and a manufacturing method. The manufacturing method comprises the steps of enabling a GaN layer and an AlGaN barrier layer sequentially to grow on a substrate to form an AlGaN / GaN heterojunction; enabling a P-GaN cap layer to grow on the heterojunction; performing mesa isolation and etching on the heterojunction to form a gatefin; forming a gate region mask pattern on the surfaces of the P-GaN cap layer and the heterojunction, and etching the P-GaN cap layer except the gate region mask pattern; manufacturing a source electrode and a drain electrode on two sides of the heterojunction; depositing gate metal in the region of the P-GaN cap layer to form a FinFET gate structure gate electrode, the gate metal covering the top and the sidewall of the P-GaN cap layer and covering the sidewall of the heterojunction; manufacturing an electrode lead. According to the device and the manufacturing method, a P-GaN cap layer structure is adopted, and a three-dimensional grid-controlled FinFET structure is combined, so that the transconductance and grid-control capabilities of the device are enhanced, and the threshold voltage and stability of the device are improved.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and in particular relates to a P-GaN cap layer FinFET enhanced device and a manufacturing method. Background technique [0002] In recent years, the third bandgap semiconductor represented by SiC and GaN has the characteristics of large bandgap, high breakdown electric field, high thermal conductivity, high saturated electron velocity and high concentration of two-dimensional electron gas at the heterojunction interface. It has received widespread attention. [0003] AlGaN / GaN heterojunction high electron mobility transistor HEMT has shown great advantages in high temperature devices and high power microwave devices. In recent years, due to the driving of high-voltage switches and high-speed circuits, GaN enhancement-mode devices have become another research hotspot. After the growth of the AlGaN / GaN heterojunction is completed, there is a large amount of two-dimensional electron gas 2...

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Problems solved by technology

[0005] 2. The AlGaN / GaN heterojunction enhanced high electron mobility transistor (HEMT) is formed by implanting F ions into the material under the gate. This method is easy to cause implantation damage during the ion implantation process, and the The depletion type formed by the method relies on charge induction, and the stability of the depletion effect has yet to be verified. Under the condition of high temperature annealing, the threshold voltage of F injection-enhanced devices may drift in the negative direction

[0006] 3. A thin AlGaN barrier layer structure is used to fabricate an AlGaN / GaN heterojunction enhanced HEMT. The use of a thin AlGaN barrier layer reduces the two-dimensional electron gas density between the source and drain electrodes, and increases the series resistance of the source and drain electrodes. Large, affecting device characteristics

[0010] 1. At present, the forward threshold voltage of the enhanced HEMT is small, and it is difficult to produce a device with a large forward threshold voltage;

[0011] 2. At present, the gate control ability of the enhanced HEMT is weak, which makes the switching characteristics of the device low;

[0012] 3. The repeatability of the manufacturing process is poor, and it is difficult to manufacture devices with stable uniformity and repeatability

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